1. Field of the Invention
The present invention relates to the finishing and polishing of metallic parts and more particularly to improvements in apparatus for performing such finishing and polishing.
2. Description of the Prior Art
Typical of the art of finishing apparatus are the following U.S. Pat. Nos. Re. 27,084; 2,882,024; 3,093,940; 3,100,088; 3,103,086; 3,161,997; 3,400,495; 3,423,884; 3,435,564; 3,466,815; 3,624,970; 3,871,135 and 3,893,266. In carrying out finishing or polishing of metallic parts, a finishing or polishing machine has been employed which includes a tub or container with a semicylindrical bottom. Such tub configurations are disclosed in certain of the above patents, including U.S. Pat. Nos. 3,093,940; 3,103,086; 3,161,997; 3,423,884; 3,435,564 and 3,624,970. Mounted directly on the tub has been a vibrator comprising an electric motor driving an eccentric weight which rotates on an axis usually parallel to the axis of the semi-cylindrical bottom of the tub. The tub and the vibrator are supported as a unit for independent movement in space on suitable spring mountings. The parts to be finished are placed in the tub along with abrasive media such as stone chips, steel balls or the like. Steel balls are generally used for polishing.
When the vibrator is actuated, the mass of polishing medium and the parts are vibrated with the result that there is minute vibratory motion between the parts and the polishing medium and the further enmasse orbital movement of the mass about an axis extending generally parallel to the axis of the semi-cylindrical bottom of the tub.
It is conventional to employ a liquid finishing compound which is added to the mass. Examples of such finishing compounds include detergents, soaps, surfactants, wetting agents and the like, typical of these being disclosed in the aforesaid U.S. Pat. No. 3,161,997. Such tubs are usually provided with means for draining off such liquid compounds as well as particulate matter in the form of fines or sediment coming either from the parts or the finishing medium present in the mass.
The aforesaid tubs are for the most part in single, compartmental form, especially those which are elongated. Those which conform more to cup or barrel shapes and are vibrated generally about an upright axis are in some instances compartmented.